Barcodes have become a widely accepted method for automatically identifying and tracking objects. A barcode symbol is typically an array of encoded elements that are printed directly on an object surface or on labels affixed to an object surface. Barcode symbols are typically read by optical techniques, such as by readers implementing scanning laser beams or handheld wands. Barcode symbols typically comprise bars and spaces with bars of varying widths representing strings of binary ones and spaces of varying widths representing binary zeros. The specific arrangement of bars or elements in a barcode symbol defines the character represented by the barcode symbol according to a set of rules and definitions specific to the code. This is referred to as the symbology of the code. The size of the bars and spaces is determined by the type of code used, as is the actual size of the bars and spaces. The number of characters per inch represented by the barcode symbol is referred to as the density of the symbol.
A desired sequence of characters are encoded based on a specific symbology to form a complete symbol. Some symbologies include start characters, stop characters and error checking characters. A variety of different symbologies have been developed. For, example, one-dimensional codes include UPC/EAN, Code 39, Code 128, Codabar and Interleaved 2 of 5. In order to increase the amount of data that can be represented in a symbol, two dimensional symbologies have been developed. A two-dimensional code standard known as Code 49 provides a two-dimensional concept of stacking rows of characters vertically instead of extending symbols bars horizontally. Another two-dimensional code is known as VERICODE (a trademark of VIRITEC Corporation), which is a checkerboard-like pattern of black or white square units. Some two-dimensional barcode symbologies (e.g., code 93) are merely extensions of one-dimensional symbologies. Some two-dimensional symbologies implement character recognitions systems (e.g., TEMA code). Regardless of the symbology being employed, the ultimate goal is to provide a barcode symbol that can maximize the amount of information encoded in the barcode symbol. However, even with the use of two-dimensional barcodes and improved symbologies, conventional barcode symbols cannot retain a sufficient amount of information.
Accordingly, there is a strong need in the art for a barcode symbol that can retain more information than conventional one-dimensional and two-dimensional symbologies.